Vehicles, such as off-highway mining vehicles “OHVs” and load-haul-dump vehicles “LHDs” used to mine and haul heavy payloads from underground mines, are well known. LHDs and other vehicles are commonly available in both diesel and electric versions and often employ motorized wheels for propelling or retarding the vehicle in an energy efficient manner. This efficiency is typically accomplished by employing a large horsepower diesel engine in conjunction with an alternator, a main traction inverter, and wheel drive assemblies housed within the tires of the vehicle. The diesel engine is directly associated with the alternator such that the diesel engine drives the alternator. The alternator powers the main traction inverter, which supplies electrical power having a controlled voltage and frequency to electric drive motors of the wheel drive assemblies. Each wheel drive assembly houses a planetary gear transmission that converts the rotation of the associated drive motor energy into a high torque low speed rotational energy output which is supplied to the wheels.
In addition to powering the main traction inverter, and thus the electric drive motors for propelling the vehicle, the alternator also powers hydraulic pumps and hydraulic motors used by various auxiliary vehicle systems, such as for bucket movement and for application of service and parking brakes.
Due to the weight of such vehicles, the payloads carried, and the environment within which such vehicles are utilized, operating these vehicles on grade can present several challenges, especially for inexperienced operators. Accordingly, it may be desirable to provide a system and method for controlling a vehicle that differ from existing systems and methods.